This is a General Research Center grant supporting five adult beds in a discrete research unit, childrens studies and an outpatient research testing and evaluation area. The studies proposed are designed by investigators from the Departments of Medicine, Pediatrics and Surgery from Boston City Hospital and University Hospital. This Center is essential for providing facilities for patient oriented research for the multitude of clinical research investigators that are associated with the Boston University School of Medicine. The facility provides investigators with (1) an environment whereby they may keep their patients in a controlled diet, sleep schedule or light environment; 2) the resources for timed collections of blood, complete collection of feces and urine, repetitive testings (eg: EKG, echocardiograms, stress testing etc.); (3) the ability to conduct testing and evaluation for pediatric, endocrinology, dermatology and cardiology patients; and (4) outpatient follow-up and outpatient protocols facilities are not available for the management of acutely ill patients or patients requiring extensive nursing care. The Center also provides a non-invasive cardiology laboratory with specialized equipment, a laboratory facility that serves the needs of investigators for the cost-effective conduct of esoteric laboratory tests, and a biostatistician for experimental design, data management, and data analysis.